Hi and welcome,
It's not actually out side of normal to 'wake up' whilst still partially in the REM sleep paralysis phase so your limbs feel weak or heavy and cause difficulty moving them normally. It happens because during the dream phase of sleep known as the rapid eye movement ie REM sleep phase, our skeletal muscles are naturally paralysed and it can take a little while before your brain registers it's time to move, the more awake you become the more your normal function returns.
Muscle twitching is one of the weird issues that could be something suggestive of a disease or absolutely nothing significant at all because it commonly occurs when lactic acid accumulates in the muscles being used, dehydration, hormonal changes, nutrition imbalances, types of medications etc etc.
You don't mention if you have neurological clinical signs of muscle weakness or not, but if all your test results are normal it's 'possible' if you mostly notice the twitching in the early morning when you are waking up and the muscle twitching and weakness feeling gets better or disappears as you getting going about your day, that what's been happening is a situation specific issue related to sleep and your answers lead you in a different direction than a neurological condition like MS.
Hope that helps.......JJ
I never know what to say when someone is diagnosed with a medical condition other than MS, so i'll give you a gentle hug and hope your neuro is MG informed!
btw I could feel a weird vibration a year or so before it became visible to others which it is all the time now, but it was a completely accidental discovery that i could make this weird feeling become visible after I gently placed a lottery ticket between my lips whilst i was cleaning the bedside table and to my shock the ticket was moving to match the weird vibration feeling i had.
I later found out the paper between the lips was one of the very old tremor tests, so you'll get why i will never ignore weird vibration feelings with muscle weakness cause they often go together. Unfortunately it's very very late over my side of the globe but if you would like me to provide you with some more information i will get back to you tomorrow, just let me know and i'll give you what i have on the topic.